Before this commit `UseTree::remove_unnecessary_braces` removed the braces
around `{self}` in `use x::y::{self};` but `use x::y::self;` is not valid
rust.
Try to generate more meaningful names in json converter
I just found out about rust-analyzer json converter, but I think it would be more convenient, if names were more useful, like using the names of the keys.
Let's look at some realistic arbitrary json:
```json
{
"user": {
"address": {
"street": "Main St",
"house": 3
},
"email": "example@example.com"
}
}
```
I think, new generated code is much easier to read and to edit, than the old:
```rust
// Old
struct Struct1{ house: i64, street: String }
struct Struct2{ address: Struct1, email: String }
struct Struct3{ user: Struct2 }
// New
struct Address1{ house: i64, street: String }
struct User1{ address: Address1, email: String }
struct Root1{ user: User1 }
```
Ideally, if we drop the numbers, I can see it being usable just as is (may be rename root)
```rust
struct Address{ house: i64, street: String }
struct User{ address: Address, email: String }
struct Root{ user: User }
```
Sadly, we can't just drop them, because there can be multiple fields (recursive) with the same name, and we can't just easily retroactively add numbers if the name has 2 instances due to parsing being single pass.
We could ignore the `1` and add number only if it's > 1, but I will leave this open to discussion and right now made it the simpler way
In sum, even with numbers, I think this PR still helps in readability
Instead of using `core::fmt::format` to format panic messages, which may in turn
panic too and cause recursive panics and other messy things, redirect
`panic_fmt` to `const_panic_fmt` like CTFE, which in turn goes to
`panic_display` and does the things normally. See the tests for the full
call stack.